On the morning of October 1, 1995, pyroclastic material which clung to the slopes of Pinatubo and surrounding mountains rushed down because of heavy rain, and turned into a lahar.
32.
The Black Tusk, a pinnacle of dark volcanic rock to the southeast, is also interpreted to be the remains of a deeply eroded volcano that was once covered with pyroclastic material.
33.
The often rapid accumulation of unconsolidated pyroclastic material on steep sideslopes tends to be inherently unstable over time; pyroclastic dams may be emplaced by the landsliding of such material into rivers and streams.
34.
The volcano consists of two craters located along a fault zone two kilometers ( 1.2 mi ) apart with associated pyroclastic material and andesitic lava flows on a high plateau at an elevation of.
35.
The current caldera was created by a cataclysmic eruption that occurred 640, 000 years ago, which released more than 240 cubic miles ( 1, 000 km?) of ash, rock and pyroclastic materials.
36.
The main cone is constructed of lava domes, lava flows, pyroclastic flows, and scoria, with most of the volcano covered by pyroclastic material, some of which extends to the southeastern margin of the.
37.
Although the northeast of the parish has significant andesite deposits and the northwest primarily basalt, the parish is composed chiefly of pyroclastic materials and projectiles, with deposits of ash located in the central area of the parish.
38.
Unlike Pompeii, the deep pyroclastic material which covered it preserved wooden and other organic-based objects such as roofs, beds, doors, food and even some 300 skeletons which were discovered in recent years along the seashore.
39.
Segula Island and the volcano formed over an underwater land surface which hosts other Aleutian volcanoes such as Andesitic lava and pyroclastic material was ejected from the underwater crater, building up over time to break the surface from nearly underwater.
40.
The island's volcanic terrain, consisting of low-density pyroclastic materials, such as the pumice stones that comprise the flanks of the �gua do Pau Massif, as susceptible to landslides resulting in the creation of lahars.
